Silver polyester-sulfonated nanoparticle composite filaments and methods of making the same

ABSTRACT

A composite filament includes a sulfonated polyester matrix and a plurality of silver nanoparticles dispersed within the matrix and methods of making thereof. Various articles can be manufactured from such composite filaments.

CROSS-REFERENCE TO RELATED APPLICATIONS

Reference is made to commonly owned and co-pending, U.S. patentapplication Ser. No. 15/098,270 (not yet assigned) entitled “SILVERNANOPARTICLE-SULFONATED POLYESTER COMPOSITE POWDERS AND METHODS OFMAKING THE SAME” to Valerie M. Farrugia et al., electronically filed onthe same day herewith, the entire disclosures of which are incorporatedherein by reference in its entirety.

BACKGROUND

The present disclosure relates to composites comprising metalnanoparticles dispersed throughout the composite matrix for use in FusedDeposition Modelling (FDM).

The medical community's reliance on three dimensional 3D printing forvarious applications is rapidly increasing and covers areas such astissue and organ fabrication, customizable devices such as prosthetics,mouth guards, orthotics, hearing aids and implants, and pharmaceuticalexploration related to controlled drug delivery and personalized drugproduction. Many of these medical applications require compositematerial that can inhibit bacterial, microbial, viral or fungal growth.Other products for 3D printing such as kitchen tools, toys, educationmaterials and countless household items also provide a favorableenvironment for bacteria growth, and therefore antibacterial compositematerials are also desirable for use in connection with these products.Due to the layered construction of 3D printed material, the potentialfor bacterial growth can be very significant, especially since certainbacterial strains can actually thrive within the detailed structuralmake-up of these materials. Washing alone does not completely sterilizethe surfaces and crevasses of these products.

Therefore, there exists a need for new materials with antibacterialproperties for 3D printing. One of the 3D printing methods is FDM, whichis a common additive manufacturing (3D printing) technique. FDM is anadditive layer manufacture technology for fabricating physical, 3Dobjects from computer-aided-design (CAD) models. FDM technology canprocess common 3D printing materials, such as, polylactic acid (PLA),acrylonitrile butadiene styrene (ABS), and high-density polyethylene(HDPE). FDM operates on the principle of heating and then extruding afeedstock material, typically as a series of stacked, patterned layers,thereby to form a build. FDM process employs moltenthermoplastic/polymers as build materials for making 3D articles via theextrusion of the molten plastics. This modelling process is a multi-stepapproach where a computer-aided design is rendered, in the case ofmedical applications this model would come from an ultrasound, computedtomography scan or magnetic resonance image. This design is thenprocessed by software which sets the desired build parameters. The filedata is used by the FDM apparatus to build the article. The spool offilament material is fed into a headed extrusion head which delivers thesemi-liquid material onto the build platform in a layer-by-layerfashion. As the model is built, the layers solidify upon deposition dueto the temperature differential of the build chamber. In some cases thehead can also extrude a removable support material which acts as ascaffold to hold the article layers in place as it cools. This supportmaterial can later be removed via heating, breaking off or washing (inultrasonic vibration tank). A layer by layer method of depositingmaterials for building a model is described in U.S. Pat. No. 5,121,329which is incorporated herein by reference. Examples of apparatus andmethods for making three-dimensional models by depositing layers offlowable modeling material are described in U.S. Pat. No. 4,749,347,U.S. Pat. No. 5,121,329, U.S. Pat. No. 5,303,141, U.S. Pat. No.5,340,433, U.S. Pat. No. 5,402,351, U.S. Pat. No. 5,503,785, U.S. Pat.No. 5,587,913, U.S. Pat. No. 5,738,817, U.S. Pat. No. 5,764,521 and U.S.Pat. No. 5,939,008. An extrusion head extrudes heated, flowable modelingmaterial from a nozzle onto a base. The base comprises a modelingsubstrate which is removably affixed to a modeling platform. Theextruded material is deposited layer-by-layer in areas defined from theCAD model, as the extrusion head and the base are moved relative to eachother in three dimensions by an x-y-z gantry system. The materialsolidifies after it is deposited to form a three-dimensional model. Itis disclosed that a thermoplastic material may be used as the modelingmaterial, and the material may be solidified after deposition bycooling.

SUMMARY

In some aspects, embodiments herein relate to filament compositescomprising a sulfonated polyester matrix and a plurality of silvernanoparticles dispersed within the matrix for use in Fused DepositionModelling (FDM) application.

In some aspects, embodiments herein relate to method comprising heatinga sulfonated polyester resin in an organic-free solvent; adding asolution of silver (I) ion to the heated resin in the organic-freesolvent to form a mixture; adding a solution of a reducing agent to themixture, thereby forming an emulsion of particles comprising asulfonated polyester matrix and a plurality of silver nanoparticlesdisposed within the sulfonated polyester matrix; aggregating theemulsion of particles to form aggregated particles; coalescing theaggregated particles to form coalesced particles; washing the coalescedparticles, thereby forming a composite powder; and extruding thecomposite powder to produce the composite filament.

In some aspects, embodiments herein relate to articles comprising acomposite powder comprising a sulfonated polyester matrix and aplurality of silver nanoparticles dispersed within the matrix, whereinthe silver nanoparticle is present in the composite filament in a rangefrom about 0.5 ppm to about 50,000 ppm; and further wherein thecomposite filament has a diameter of from about 0.5 mm to about 5 mm.

BRIEF DESCRIPTION OF DRAWINGS

Various embodiments of the present disclosure will be described hereinbelow with reference to the figures wherein:

FIG. 1 shows a schematic of a possible mechanism of sodio sulfonatedpolyester self-assembly in the presence of Ag.

FIG. 2 shows a schematic of a possible mechanism of the preparation ofdry particles for filament fabrication.

FIG. 3 is a grayscale image showing BSPE-AgNP antibacterial particlesaccording to an embodiment of the disclosure (Example 3) fused ontoglass microfiber membrane.

DETAILED DESCRIPTION

As used herein, “a,” “an,” “the,” “at least one,” and “one or more” areused interchangeably. Thus, for example, a coating composition thatcomprises “an” additive can be interpreted to mean that the coatingcomposition includes “one or more” additives.

Also herein, the recitations of numerical ranges includes disclosure ofall subranges included within the broader range (e.g., 1 to 5 discloses1 to 4, 1 to 3, 1 to 2, 2 to 4, 2 to 3, . . . etc.).

The present disclosure provides a composite filament, more specifically,a sulfonated polyester polymeric composite filament containing silvernanoparticles (AgNPs), for use in Fused Deposition Modelling (FDM)application.

The class of AgNP polymer composites is more suitable for antibacterialapplications compared to ionic and bulk silver, because silver salts mayrelease silver too quickly and uncontrollably while bulk silver is veryinefficient in releasing active silver species. AgNPs are known fortheir antibacterial properties; however the exact mechanism ofantibacterial activity using AgNPs is poorly understood. The AgNPs mayinteract with the cell wall of the bacteria, consequently destabilizingthe plasma-membrane potential and reducing the levels of intracellularadenosine triphosphate (ATP) resulting in bacterial cell death.Alternatively, AgNPs might play a role in the formation of reactiveoxygen species (ROS) which is responsible for the cytotoxicity ofbacteria cells in presence of AgNPs. “Potential Theranostics Applicationof Bio-Synthesized Silver Nanoparticles (4-in-1 System),” Theranostics2014; 4(3):316-335. Furthermore, AgNPs have been reported to take partin chemical reduction-oxidation reactions as a catalyst by facilitatingelectron transfer between an electron donor and electron acceptor.“Micelle bound redox dye marker for nanogram level arsenic detectionpromoted by nanoparticles,” New J. Chem., 2002, 26, 1081-1084.

The FDM composite filament of the present disclosure may be synthesizedfrom sulfonated polyester-silver nanoparticles (SPE-AgNPs) where theSPE-AgNPs are aggregated from nano-sized to micron-sized then extrudedinto filaments. More specifically, a dry composite powder is firstformed from the aggregation of self-dispersible sulfonated polyester(SPE) with embedded silver nanoparticles (AgNPs) that are simultaneouslyproduced from silver nitrate with or without a reducing agent during theself-assembly of the sulfonated polyester resin particles in water.Subsequently, the dry composite powder is then processed into filamentsfrom its powdered form, where the powdered form may optionally includeadditives and/or fillers.

The present disclosure pertain to polymeric filaments comprising asulfonated polyester matrix and a plurality of silver nanoparticles maybe prepared according to procedures disclosed in U.S. Pat. No. 6,866,807U.S. Pat. No. 5,121,329, U.S. Pat. No. 6,730,252, U.S. Pat. No.3,046,178, U.S. Pat. No. 6,923,634, U.S. Pat. No. 2,285,552, U.S. Pat.No. 4,012,557, U.S. Pat. No. 4,913,864, US Patent Publication20040222561, and US Patent Publication 20150084222.

SPE-AgNPs

Certain embodiments herein provide methods of synthesizing silvernanoparticles (AgNPs) by reduction of silver (I) ion simultaneouslyduring the self-assembly of sodio sulfonated polyester resin particlesin water. The methods which employ water as the bulk solvent areenvironmentally friendly being free of organic solvents (or organic-freesolvents). The methods are efficient requiring minimal time to preparethe polymer metal nanocomposites. Without being bound by theory it ispostulated that silver ions are trapped within the polymer matrix duringthe self-assembly of the sodio sulfonated polyester while simultaneouslybeing reduced to AgNPs. The sulfonated polyester-silver nanoparticles(SPE-AgNPs) are simultaneously synthesized during the self-assembly ordispersing of polymer in water as indicated in FIG. 1. Thus, the sodiosulfonated polyester serves as both a carrier for the silver ions and anorganic matrix for the in situ synthesis of silver nanocomposites. Thereducing agent is added during the self-assembly of sodio sulfonatedpolyester to reduce silver nitrate into silver nanoparticles (AgNPs)resulting in well dispersed particles. The polyester matrix plays animportant role as it is postulated to inhibit the agglomeration ofAgNPs. Meanwhile, the porosity of the sulfonated polyester allows thesilver ions to diffuse and/or absorb throughout the polymer matrixallowing unhindered interaction with the sulfonate functional groups ofthe polyester. The reducing agent employed in the reduction of silverion also freely diffuses throughout the polyester matrix and promotesthe formation of well-dispersed AgNPs on the surface and interior of thepolyester particles. Advantageously, the process minimizes nanoparticleagglomeration that plagues conventional methods with pre-formednanoparticles. The sulfonated polymer matrix has an important role inkeeping the AgNPs dispersed as well as maintaining overall chemical andmechanical stability of the composite.

Silver has many useful properties, including its antibacterial,antimicrobial, antifungal, antiviral properties. These novel propertiesof the silver nanocomposite materials disclosed herein make them usefulin applications such as electronics components, optical detectors,chemical and biochemical sensors and similar devices. The ability tominiaturize any of these materials is a substantial benefit of thesilver nanocomposite materials described herein.

The sulfonated polyester resins disclosed herein have been selected tohave a hydrophobic backbone while presenting hydrophilic sulfonategroups attached along the chain. Without being bound by theory, whenplaced in water and heated, the hydrophobic portions may interact witheach other to form a hydrophobic core with the hydrophilic sulfonategroups facing the surrounding water resulting in the sulfonatedpolyester self-assembling into a higher order, spherical nanoparticlewithout the requirement of additional reagents. Thus, there is a higherorder involving the amphiphilic polyester, in which the hydrophobicbackbone, which is insoluble in water, and the water-soluble hydrophilicsulfonate groups, operate as macrosurfactants. This results inself-association, self-assembly, self-dispersible nanoparticles inaqueous medium to yield micelle-like aggregates. The formation of silvernanoparticles within and surrounding the micelles is a secondaryoccurrence upon addition of silver nitrate and reducing agent.

In embodiments, there are provided composites comprising a sulfonatedpolyester matrix, and a plurality of silver nanoparticles dispersedwithin the matrix.

In embodiments, the sulfonated polyester matrix is a branched polymer.In embodiments, the sulfonated polyester matrix is a linear polymer. Theselection of branched or linear polymer may depend on, inter alia, thedownstream application of the composite product. Linear polymers can beused to create strands of fibers or form a strong mesh-like structure.Branched polymers may be useful to confer thermoplastic properties onthe resultant composite material.

In embodiments, sulfonated polyesters of the present disclosure can be ahomopolymer of one ester monomer or a copolymer of two or more estermonomers. Examples of suitable sulfonated polyesters include thosedisclosed in U.S. Pat. Nos. 5,348,832, 5,593,807, 5,604,076, 5,648,193,5,658,704, 5,660,965, 5,840,462, 5,853,944, 5,916,725, 5,919,595,5,945,245, 6,054,240, 6,017,671, 6,020,101, 6,140,003, 6,210,853 and6,143,457, the disclosures of each of which are totally incorporatedherein by reference.

In embodiments, sulfonated polyesters of the present disclosure can behydrogen or a salt of a random sulfonated polyester, including salts(such as metal salts, including aluminum salts, salts of alkali metalssuch as sodium, lithium, and potassium, salts of alkaline earth metalssuch as beryllium, magnesium, calcium, and barium, metal salts oftransition metals, such as vanadium, iron, cobalt, copper, and the like,as well as mixtures thereof) of poly(1,2-propylene-5-sulfoisophthalate),poly(neopentylene-5-sulfoisophthalate),poly(diethylene-5-sulfoisophthalate),copoly(1,2-propylene-5-sulfoisophthalate)-copoly-(1,2-propylene-terephthalatephthalate),copoly(1,2-propylene-diethylene-5-sulfoisophthalate)-copoly-(1,2-propylene-diethylene-terephthalatephthalate),copoly(ethylene-neopentylene-5-sulfoisophthalate)-copoly-(ethylene-neopentylene-terephthalate-phthalate),copoly(propoxylated bisphenol A)-copoly-(propoxylated bisphenolA-5-sulfoisophthalate),copoly(ethylene-terephthalate)-copoly-(ethylene-5-sulfo-isophthalate),copoly(propylene-terephthalate)-copoly-(propylene-5-sulfo-isophthalate),copoly(diethylene-terephthalate)-copoly-(diethylene-5-sulfo-isophthalate),copoly(propylene-diethylene-terephthalate)-copoly-(propylene-diethylene-5-sulfoisophthalate),copoly(propylene-butylene-terephthalate)-copoly(propylene-butylene-5-sulfo-isophthalate),copoly(propoxylated bisphenol-A-fumarate)-copoly(propoxylated bisphenolA-5-sulfo-isophthalate), copoly(ethoxylatedbisphenol-A-fumarate)-copoly(ethoxylatedbisphenol-A-5-sulfo-isophthalate), copoly(ethoxylatedbisphenol-A-maleate)-copoly(ethoxylatedbisphenol-A-5-sulfo-isophthalate), copoly(propylene-diethyleneterephthalate)-copoly(propylene-5-sulfoisophthalate),copoly(neopentyl-terephthalate)-copoly-(neopentyl-5-sulfoisophthalate),and the like, as well as mixtures thereof.

In general, the sulfonated polyesters may have the following generalstructure, or random copolymers thereof in which the n and p segmentsare separated.

wherein R is an alkylene of, for example, from 2 to about 25 carbonatoms such as ethylene, propylene, butylene, oxyalkylenediethyleneoxide, and the like; R′ is an arylene of, for example, fromabout 6 to about 36 carbon atoms, such as a benzylene, bisphenylene,bis(alkyloxy) bisphenolene, and the like; and p and n represent thenumber of randomly repeating segments, such as for example from about 10to about 100,000.

Examples of the sulfonated polyesters further include those disclosed inU.S. Pat. No. 7,312,011 which is incorporated herein by reference in itsentirety. Specific examples of amorphous alkali sulfonated polyesterbased resins include, but are not limited to,copoly(ethylene-terephthalate)-copoly-(ethylene-5-sulfo-isophthalate),copoly(propylene-terephthalate)-copoly(propylene-5-sulfo-isophthalate),copoly(diethylene-terephthalate)-copoly(diethylene-5-sulfo-isophthalate),copoly(propylene-diethylene-terephthalate)-copoly(propylene-diethylene-5-sulfo-isophthalate),copoly(propylene-butylene-terephthalate)-copoly(propylene-butylene-5-sulfo-isophthalate),copoly(propoxylated bisphenol-A-fumarate)-copoly(propoxylated bisphenolA-5-sulfo-isophthalate), copoly(ethoxylatedbisphenol-A-fumarate)-copoly(ethoxylatedbisphenol-A-5-sulfo-isophthalate), and copoly(ethoxylatedbisphenol-A-maleate)-copoly(ethoxylatedbisphenol-A-5-sulfo-isophthalate), and wherein the alkali metal is, forexample, a sodium, lithium or potassium ion. Examples of crystallinealkali sulfonated polyester based resins alkalicopoly(5-sulfoisophthaloyl)-co-poly(ethylene-adipate), alkalicopoly(5-sulfoisophthaloyl)-copoly(propylene-adipate), alkalicopoly(5-sulfoisophthaloyl)-copoly(butylene-adipate), alkalicopoly(5-sulfo-isophthaloyl)-copoly(pentylene-adipate), and alkalicopoly(5-sulfo-iosphthaloyl)-copoly(octylene-adipate), alkalicopoly(5-sulfo-isophthaloyl)-copoly(ethylene-adipate), alkalicopoly(5-sulfo-isophthaloyl)-copoly (propylene-adipate), alkalicopoly(5-sulfo-isophthaloyl)-co-poly(butylene-adipate), alkalicopoly(5-sulfo-isophthaloyl)-copoly(pentylene-adipate), alkalicopoly(5-sulfo-isophthaloyl)-copoly(hexylene-adipate), alkalicopoly(5-sulfo-isophthaloyl)-copoly(octylene-adipate), alkalicopoly(5-sulfoisophthaloyl)-copoly(ethylene-succinate), alkalicopoly(5-sulfoisophthaloyl-copoly(butylene-succinate), alkalicopoly(5-sulfoisophthaloyl)-copoly(hexylene-succinate), alkalicopoly(5-sulfoisophthaloyl)-copoly(octylene-succinate), alkalicopoly(5-sulfo-isophthaloyl)-copoly(ethylene-sebacate), alkalicopoly(5-sulfo-isophthaloyl)-copoly(propylene-sebacate), alkalicopoly(5-sulfo-isophthaloyl)-copoly(butylene-sebacate), alkalicopoly(5-sulfo-isophthaloyl)-copoly(pentylene-sebacate), alkalicopoly(5-sulfo-isophthaloyl)-copoly(hexylene-sebacate), alkalicopoly(5-sulfo-isophthaloyl)-copoly(octylene-sebacate), alkalicopoly(5-sulfo-isophthaloyl)-copoly(ethylene-adipate), alkalicopoly(5-sulfo-isophthaloyl)-copoly(propylene-adipate), alkalicopoly(5-sulfo-iosphthaloyl)-copoly(butylene-adipate), alkalicopoly(5-sulfo-isophthaloyl)-copoly(pentylene-adipate), alkalicopoly(5-sulfo-isophthaloyl)copoly(hexylene-adipate),poly(octylene-adipate), and wherein the alkali is a metal such assodium, lithium or potassium. In embodiments, the alkali metal issodium.

The sulfonated polyesters suitable for use in the present disclosuremust be able to be melt-processed into a filament of appropriatediameter for the rate of extrusion of the particular FDM apparatus.

The sulfonated polyesters suitable for use in the present disclosure mayhave a glass transition (Tg) temperature of from about 45° C. to about95° C., or from about 52° C. to about 70° C., as measured by theDifferential Scanning calorimeter. The sulfonated polyesters may have anumber average molecular weight of from about 2,000 g per mole to about150,000 g per mole, from about 3,000 g per mole to about 50,000 g permole, or from about 6,000 g per mole to about 15,000 g per mole, asmeasured by the Gel Permeation Chromatograph. The sulfonated polyestersmay have a weight average molecular weight of from about 3,000 g permole to about 300,000 g per mole, from about 8,000 g per mole to about90,000 g per mole, or from about 10,000 g per mole to about 60,000 g permole, as measured by the Gel Permeation Chromatograph. The sulfonatedpolyesters may have a polydispersity of from about 1.6 to about 100,from about 2.0 to about 50, or from about 5.0 to about 30, as calculatedby the ratio of the weight average to number average molecular weight.

The linear amorphous polyester resins are generally prepared by thepolycondensation of an organic diol and a diacid or diester, at leastone of which is sulfonated or a sulfonated difunctional monomer beingincluded in the reaction, and a polycondensation catalyst. For thebranched amorphous sulfonated polyester resin, the same materials may beused, with the further inclusion of a branching agent such as amultivalent polyacid or polyol.

Examples of diacid or diesters selected for the preparation of amorphouspolyesters include dicarboxylic acids or diesters selected from thegroup consisting of terephthalic acid, phthalic acid, isophthalic acid,fumaric acid, maleic acid, itaconic acid, succinic acid, succinicanhydride, dodecylsuccinic acid, dodecylsuccinic anhydride, glutaricacid, glutaric anhydride, adipic acid, pimelic acid, suberic acid,azelic acid, dodecanediacid, dimethyl terephthalate, diethylterephthalate, dimethylisophthalate, diethylisophthalate,dimethylphthalate, phthalic anhydride, diethylphthalate,dimethylsuccinate, dimethylfumarate, dimethylmaleate, dimethylglutarate,dimethyladipate, dimethyl dodecylsuccinate, and mixtures thereof. Theorganic diacid or diester are selected, for example, from about 45 toabout 52 mole percent of the resin. Examples of diols utilized ingenerating the amorphous polyester include 1,2-propanediol,1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol,pentanediol, hexanediol, 2,2-dimethylpropanediol,2,2,3-trimethylhexanediol, heptanediol, dodecanediol,bis(hyroxyethyl)-bisphenol A, bis(2-hyroxypropyl)-bisphenol A,1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, xylenedimethanol,cyclohexanediol, diethylene glycol, bis(2-hydroxyethyl) oxide,dipropylene glycol, dibutylene, and mixtures thereof. The amount oforganic diol selected can vary, and more specifically, is, for example,from about 45 to about 52 mole percent of the resin.

Alkali sulfonated difunctional monomer examples, wherein the alkali islithium, sodium, or potassium, include dimethyl-5-sulfo-isophthalate,dialkyl-5-sulfo-isophthalate-4-sulfo-1,8-naphthalic anhydride,4-sulfo-phthalic acid, 4-sulfophenyl-3,5-dicarbomethoxybenzene,6-sulfo-2-naphthyl-3,5-dicarbomethoxybenzene, sulfo-terephthalic acid,dimethyl-sulfo-terephthalate, dialkyl-sulfo-terephthalate,sulfo-ethanediol, 2-sulfo-propanediol, 2-sulfo-butanediol,3-sulfo-pentanediol, 2-sulfo-hexanediol, 3-sulfo-2-methylpentanediol,N,N-bis(2-hydroxyethyl)-2-aminoethane sulfonate,2-sulfo-3,3-dimethylpent-anediol, sulfo-p-hydroxybenzoic acid, mixturesthereto, and the like. Effective difunctional monomer amounts of, forexample, from about 0.1 to about 2 weight percent of the resin can beselected.

Branching agents for use in forming the branched amorphous sulfonatedpolyester include, for example, a multivalent polyacid such as1,2,4-benzene-tricarboxylic acid, 1,2,4-cyclohexanetricarboxylic acid,2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylicacid, 1,2,5-hexanetricarboxylic acid,1,3-dicarboxyl-2-methyl-2-methylene-carboxylpropane,tetra(methylene-carboxyl)methane, and 1,2,7,8-octanetetracarboxylicacid, acid anhydrides thereof, and lower alkyl esters thereof, 1 toabout 6 carbon atoms; a multivalent polyol such as sorbitol,1,2,3,6-hexanetetrol, 1,4-sorbitane, pentaerythritol, dipentaerythritol,tripentaerythritol, sucrose, 1,2,4-butanetriol, 1,2,5-pentatriol,glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol,trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene,mixtures thereof, and the like. The branching agent amount selected is,for example, from about 0.1 to about 5 mole percent of the resin.

Polycondensation catalyst examples for amorphous polyesters includetetraalkyl titanates, dialkyltin oxide such as dibutyltin oxide,tetraalkyltin such as dibutyltin dilaurate, dialkyltin oxide hydroxidesuch as butyltin oxide hydroxide, aluminum alkoxides, alkyl zinc,dialkyl zinc, zinc oxide, stannous oxide, or mixtures thereof; and whichcatalysts are selected in amounts of, for example, from about 0.01 molepercent to about 5 mole percent based on the starting diacid or diesterused to generate the polyester resin.

In particular embodiments, the sulfonated polyester matrix comprises apolyol monomer unit selected from the group consisting oftrimethylolpropane, 1,2-propanediol, diethylene glycol, and combinationsthereof.

In particular embodiments, the sulfonated polyester matrix comprises adiacid monomer unit selected from the group consisting of terephthalicacid, sulfonated isophthalic acid, and combinations thereof.

In embodiments, the sulfonated polyester-silver core nanoparticles mayhave a particle size in a range from about 5 nm to about 500 nm, orabout 10 to about 200 nm, or about 20 to about 100 nm. A core particlesize of less than 100 nm may be useful for reinforcement of polymermatrices without disturbing transparency and other properties ofcoatings. Tsavalas, J. G. et al. J. Appl. Polym. Sci., 87:1825-1836(2003). As used herein, references to “particle size” will generallyrefer to D₅₀ mass-median-diameter (MMD) or the log-normal distributionmass median diameter. The MMD is considered to be the average particlediameter by mass.

In embodiments, the silver nanoparticles may include solely elementalsilver or may be a silver composite, including composites with othermetals. Such metal-silver composite may include either or both of (i)one or more other metals and (ii) one or more non-metals. Suitable othermetals include for example Al, Au, Pt, Pd, Cu, Co, Cr, In, and Ni,particularly the transition metals for example Au, Pt, Pd, Cu, Cr, Ni,and mixtures thereof. Exemplary metal composites are Au—Ag, Ag—Cu,Au—Ag—Cu, and Au—Ag—Pd. Suitable non-metals in the metal compositeinclude for example Si, C, and Ge. The various components of the silvercomposite may be present in an amount ranging for example from about0.01% to about 99.9% by weight, particularly from about 10% to about 90%by weight. In embodiments, the silver composite is a metal alloycomposed of silver and one, two or more other metals, with silvercomprising for example at least about 20% of the nanoparticles byweight, particularly greater than about 50% of the nanoparticles byweight. Unless otherwise noted, the weight percentages recited hereinfor the components of the silver-containing nanoparticles do not includethe stabilizer.

Silver nanoparticles composed of a silver composite can be made forexample by using a mixture of (i) a silver compound (or compounds,especially silver (I) ion-containing compounds) and (ii) another metalsalt (or salts) or another non-metal (or non-metals) during thereduction step.

In embodiments, the silver nanoparticles have a particle size in a rangefrom about 2 to about 50 nm, or about 10 to about 50 nm or about 20 toabout 50 nm. Silver nanoparticles of diameter less than 100 nm absorblight primarily below 500 nm. This property is useful as it allows theAgNPs to be used in combination with fluorescence emission detectionsince most fluorophores emit at a wavelength above 500 nm, thusminimizing quenching of the signal.

In embodiments, the sulfonated polyester-silver core nanoparticles mayfurther comprise nanostructured materials, such as, without limitation,carbon nanotubes (CNTs, including single-walled, double-walled, andmulti-walled), graphene sheet, nanoribbons, nano-onions, hollownanoshell metals, nano-wires and the like. In embodiments, CNTs may beadded in amounts that enhance electrical and thermal conductivity.

A shell polymer may be disposed over the sulfonated polyester-silvercore nanoparticles. In embodiments, the shell polymer disposed about thesulfonated polyester-silver core nanoparticles comprises a styrenemonomer, including substituted or unsubstituted styrenes. Inembodiments, the shell polymer further comprises at least one vinylmonomer selected from the group consisting of methyl acrylate, ethylacrylate, butyl acrylate, isobutyl acrylate, dodecyl acrylate, n-octylacrylate, 2-ethylhexyl acrylate, 2-chloroethyl acrylate, phenylacrylate, β-carboxyethyl acrylate, methyl α-chloro acrylate, methylmethacrylate, ethyl methacrylate, butyl methacrylate, butadiene,isoprene, methacrylonitrile, acrylonitrile, methyl vinyl ether, vinylisobutyl ether, vinyl ethyl ether, vinyl acetate, vinyl propionate,vinyl benzoate, vinyl butyrate, vinyl methyl ketone, vinyl hexyl ketone,and methyl isopropenyl ketone, vinylidene chloride, vinylidene chlorofluoride, N-vinylindole, N-vinyl pyrrolidene, acrylic acid, methacrylicacid, acrylamide, methacrylamide, vinyl pyridine, vinyl pyrrolidone,vinyl N-methylpyridinium chloride, vinyl naphthalene, p-chlorostyrene,vinyl chloride, vinyl fluoride, ethylene, propylene, butylene, andisobutylene.

In embodiments, the shell polymer has a thickness from about 0.5 nm toabout 100 nm, or from about 1.0 nm to about 50 nm, or from about 1.5 nmto about 20 nm.

In embodiments, the shell polymer confers to the sulfonatedpolyester-silver core nanoparticles one or more properties selected fromthe group consisting of (a) methanol resistance, (b) resistance tothermal degradation, and (c) acid/base resistance. With respect tomethanol resistance, it is postulated that the polymer shell protectsthe core sulfonated polyester/AgNP composite from gelation. Inembodiments, no more than about 10% material dissolves when, forexample, a styrene shell is used.

With respect to resistance to thermal degradation, polymershell-protected composites show only about 50% degradation at 400° C.,while uncoated SPE-AgNP composites show about 80% decomposition at 400°C. The thermal stability of the styrene-coated composites, inparticular, appears to be more complex than that of polystyrene alone.The first major mass loss of the styrene-coated composites starts around300° C. (30.65%) but becomes more stable and degrades much slower thanuncoated samples and polystyrene control.

With respect to acid/base resistance, addition of a polymer shell, suchas styrene, to the sulfonated polyester-silver core nanoparticles mayprovide an improvement under basic conditions by 20 to 30%. Finally, apolymer shell, such as polystyrene, around the SPE/AgNp core providessubstantially improved rigidity and strength of the organic/inorganichybrid composite core materials.

Composite Filaments Synthesized from Sulfonated Polyester-SilverNanoparticles SPE-AgNPs

Composite powders as described herein are first prepared from thesulfonated polyester-silver nanoparticles (SPE-AgNPs), and then thecomposite powders are converted to composite filaments by filamentfabrication.

The sulfonated polyester-silver nanoparticles (SPE-AgNPs) describedherein can be produced by a method comprising heating a sulfonatedpolyester resin in an organic-free solvent, adding a solution of silver(I) ion to the heated resin in the organic-free solvent to form amixture, adding a solution of a reducing agent to the mixture, therebyforming an emulsion of composite particles comprising a sulfonatedpolyester matrix and a plurality of silver nanoparticles disposed withinthe sulfonated polyester matrix. The term “organic-free solvent” refersto media that does not contain any organic solvent, an aqueous mediasuch as water is considered to be an organic-free solvent. Inembodiments, heating is conducted at a temperature from about 65° C. toabout 90° C. Temperatures in this range are appropriate for both theinitial dissolution of the polymer resin and subsequent reduction in thepresence of silver ion. In embodiments, a source of silver (I) ion isselected from silver nitrate, silver sulfonate, silver fluoride, silverperchlorate, silver lactate, silver tetrafluoroborate, silver oxide,silver acetate. Silver nitrate is a common silver ion precursor for thesynthesis of AgNPs. In embodiments, the reducing agent is selected fromascorbic acid, trisodium citrate, glucose, galactose, maltose, lactose,gallic acid, rosmarinic acid, caffeic acid, tannic acid, dihydrocaffeicacid, quercetin, sodium borohydride, potassium borohydride, hydrazinehydrate, sodium hypophosphite, hydroxylamine hydrochloride. Inembodiments, reducing agents for the synthesis of AgNPs may includesodium borohydride or sodium citrate. Selection of appropriate reducingagent may provide access to desirable nanoparticle morphologies. Forexample, ascorbic acid was observed to provide silver nanoplate formsduring a study directed to quantitation of vitamin C tablets. Rashid etal. J. Pharm. Sci. 12(1):29-33 (2013).

Composite powders may be prepared by conventional (ground andclassification) or chemical (emulsion aggregation) means. U.S. Pat. Nos.5,111,998, 5,147,753, 5,272,034, and 5,393,630 disclose conventionaltoner manufacturing processes are incorporated in their entirety byreference herein.

Composite powders may be prepared by emulsion aggregation means. Themethod to prepare the microparticles from polymeric coated sulfonatedpolyester-silver nanoparticles SPE-AgNPs is similar to the process knownto generate toner particles (emulsion aggregation or EA). Particles ofnarrow size distribution and controllable particle size can be achievedwith the aid of aggregating agents such as zinc acetate, magnesiumchloride salts, aluminum sulfate and polyaluminum chloride (PAC). Theparticle morphology can be controlled via temperature, time, andstirring to provide particles that range from an irregularly shaped oran imperfect spherical to a near or perfect spherical. Any suitableemulsion aggregation procedure may be used in forming the emulsionaggregation composite particles without restriction. FIG. 3 shows anemulsion aggregation process for preparing dry particles for FusedDeposition Modelling (FDM) according to certain embodiments of thepresent disclosure. These procedures typically include the process stepsof aggregating an emulsion of particles comprising a sulfonatedpolyester matrix and a plurality of silver nanoparticles disposed withinthe sulfonated polyester matrix, and one or more additional optionaladditives to form aggregated particles, subsequently coalescing theaggregated particles, and then recovering, optionally washing andoptionally drying the obtained emulsion aggregation particles. However,in embodiments, the process is modified by the addition of a coalescentagent (or coalescence aid agent) prior to the coalescence. This additionof the coalescent agent provides toner particles having improvedspheroidization, and allows the coalescence to be conducted in a shortertime, at a lower process temperature, or both. In embodiments, prior tothe aggregation step, water is added to the SPE-AgNPs to form a slurry.In embodiments, the addition of water affords a total solid contentbased on the total weight of the slurry of from about 1% to about 40%,from about 5% to about 20%, or from about 10% to about 50%. Theaggregating step includes heating the slurry to a temperature of fromabout 30° C. to about 80° C., from about 40° C. to about 70° C., or fromabout 50° C. to about 68° C. The duration of the aggregation step may befrom about 1 minute to about 8 hours, from about 30 minutes to about 6hour, or from about 60 minutes to about 4 hours. The coalescing stepincludes heating the aggregated particles to a temperature of from about30° C. to about 95° C., from about 40° C. to about 95° C., or from about60° C. to about 90° C. The duration of the coalescing step may be fromabout 1 minute to about 6 hours, from about 30 minutes to about 4 hour,or from about 60 minutes to about 3 hours.

Examples of suitable coalescent agents include, but are not limited to,benzoic acid alkyl esters, ester-alcohols, glycol-ether type solvents,long-chain aliphatic alcohols, aromatic alcohols, mixtures thereof, andthe like. Examples of benzoic acid alkyl esters include benzoic acidalkyl esters where the alkyl group, which can be straight or branched,substituted or unsubstituted, has from about 2 to about 30 carbon atoms,such as decyl or isodecyl benzoate, nonyl or isononyl benzoate, octyl orisooctyl benzoate, 2-ethylhexyl benzoate, tridecyl or isotridecylbenzoate, 3,7-dimethyloctyl benzoate, 3,5,5-trimethylhexyl benzoate,mixtures thereof, and the like. Specific commercial examples of suchbenzoic acid alkyl esters include VELTA® 262 (isodecyl benzoate) andVELTA® 368 (2-ethylhexyl benzoate), available from Vlesicol ChemicalCorporation. Examples of ester-alcohols include hydroxyalkyl esters ofalkanoic acids where the alkyls group, which can be straight orbranched, substituted or unsubstituted, independently have from about 2to about 30 carbon atoms, such as 2,2,4-trimethylpentane-1,3-diolmonoisobutyrate. Specific commercial examples of such ester-alcoholsinclude TEXANOL® (2,2,4-trimethylpentane-1,3-diol monoisobutyrate)available from Eastman Chemical Company. Examples of glycol-ether typesolvents include diethylene glycol monomethylether acetate, diethyleneglycol monobutylether acetate, butyl carbitol acetate (BCA), and thelike. Examples of long-chain aliphatic alcohols include those where thealkyl group is from about 5 to about 20 carbon atoms, such asethylhexanol, octanol, dodecanol, and the like. Examples of aromaticalcohols include benzyl alcohol, and the like.

In embodiments, the coalescent agent (or coalescence aid agent)evaporates during later stages of the emulsion aggregation process orduring coalescence, such as during the heating step that is generallynear or above the glass transition temperature of the sulfonatedpolyester resin. The final composite powders are thus free of, oressentially or substantially free of, any remaining coalescent agent. Tothe extent that any remaining coalescent agent may be present in thefinal powder composites, the amount of remaining coalescent agent issuch that it does not affect any properties or performance of thecomposite powders.

The coalescent agent can be added prior to the coalescence in anydesired or suitable amount. For example, the coalescent agent can beadded in an amount of from about 0.01 to about 10 percent by weight,based on the solids content in the reaction medium. For example, thecoalescent agent can be added in an amount of from about 0.05 or fromabout 20.0, from about 0.1 to about 10.0 percent by weight, or fromabout 0.5 to about 5.0 percent by weight, based on the solids content inthe reaction medium. In embodiments, the coalescent agent can be addedprior to or at any time between aggregation and coalescence or upfrontbefore heating.

Optional additives such as waxes, pigments, ceramics, carbon fiber ornanotubes, and fillers may be included in the composite powder. Theseadditives may be added prior to or during the aggregation step orupfront before heating. The amount of additives present in the compositepowder may be from about 0% to about 30%, from about 0% to about 20%, orfrom about 0% to about 10% by weight of the total weight of thecomposite powder.

The composite powders may be then fabricated into filaments. Thecomposite filament of the present disclosure may be manufactured usingan extrusion process. The composite powders may be first loaded into amelt flow index (MFI) instrument (also referred to as an extrusionplastometer) and equilibrated at a temperature of from about 60° C. toabout 250° C., from about 60° C. to about 190° C., or from about 80° C.to about 150° C., for a period of time, such as from about 1 to about 90minutes, from about 1 to about 60 minutes, from about 5 to about 45minutes. After equilibration, the material obtained may be then extrudedwith a weight in a range of from about 1 kg to about 30 kg, from about 1kg to about 20 kg, or from about 2 kg to about 10 kg, through a 0.5-5 mmdiameter die to fabricate the FDM filament. In embodiments, thecomposite filament is in the form of a cylinder with a diameter of, forexample, about 0.5 mm to about 5.0 mm, about 1.5 mm to about 3.0 mm,about 1.75 mm to about 3.0 mm. The length of the composite filament canbe in any length, for example, for testing purposes, from about 2 ft toabout 100 ft, from about 2 ft to about 50 ft, from about 5 ft to about20 ft, and for commercial purposes, from about 50 ft to 2000 ft, fromabout 300 ft to about 1500 ft, or from about 400 ft to about 1300 ft.

The process of filament fabrication merely changes the physical appearof the composite and does not alter the material or content of thecomposite. Thus, the filament of the present disclosure comprises thesame sulfonated polyester matrix and silver nanoparticles as describedherein. In embodiments, the filament comprises the same sulfonatedpolyester-silver core nanoparticles as described herein. In embodiments,the filament comprises the same sulfonated polyester-silver corenanoparticles having a shell polymer disposed over as described herein.

In embodiments, a loading of silver nanoparticle is present in thecomposite filaments in a range from about 0.5 ppm to about 50,000 ppm,from about 5 ppm to about 5,000, from about 10 ppm to about 2,500, ppm,or from about 50 ppm to about 1,000 ppm. Loading concentrations ofsilver within this range can be used for antibacterial applications.Lower concentrations of silver might be sufficient for catalyticapplications; concentrations of AgNPs as low as 1 ppm have been used.Ghosh, S. K. et al. Langmuir. 18(23):8756-8760 (2002).

In embodiments, methods disclosed herein may be particularly well-suitedfor making composites with relatively low solids content. Under suchconditions, silver ion and reducing agent may readily diffuse throughthe polymer matrix. In the case of silver ion, such ready diffusion mayimprove uniformity of distribution of silver throughout the matrix.

In embodiments, there are provided articles comprising a plurality ofcomposite filament as described herein, the composite filaments maycomprise a core particle comprising a sulfonated polyester matrix and aplurality of silver nanoparticles dispersed throughout the matrix and ashell polymer disposed about the core particle.

The properties of the composite herein make them useful in variousapplications including, without limitation, electronics components,optical detectors, chemical and biochemical sensors and devices. Theability to miniaturize any of these materials is a major benefit ofusing the nanoscale composite structures herein. Other areas of interestthat employ the composite powder herein include, without limitation,antibacterial applications, optical bi-stability, textiles,photoresponsivity, environmental, biological, medicine (membranes andseparation devices), functional smart coatings, fuel and solar cells,and as catalysts.

The following Examples are being submitted to illustrate embodiments ofthe present disclosure. These Examples are intended to be illustrativeonly and are not intended to limit the scope of the present disclosure.Also, parts and percentages are by weight unless otherwise indicated. Asused herein, “room temperature” refers to a temperature of from about20° C. to about 25° C.

EXAMPLES

General Process: Composite preparation involves dispersing a branchedsodio sulfonated polyester (BSPE) in water at about 90° C., followed byaddition of a silver nitrate solution and lastly a mild reducing agentsuch as trisodium citrate or ascorbic acid is added. The reduction ofAg(I) to Ag(0) occurs after the addition of Ag(I) salt to the BSPE andis facilitated by the reducing agent. AgNP-BSPE systems that aresynthesized via the trisodium citrate reductant route can also utilizethe citrate cap for further applications such as biosensors where thecitrate ligand is employed for analyte binding for quantitative orqualitative analysis of analyte concentration in a sample.

Example 1

This example describes the preparation of a branched sodio sulfonatedamorphous polyesters (BSPE) according to embodiments of the presentdisclosure

A branched amorphous sulfonated polyester resin comprised of 0.425 moleequivalent of terephthalate, 0.080 mole equivalent of sodium5-sulfoisophthalic acid, 0.4501 mole equivalent of 1,2-propanediol, and0.050 mole equivalent of diethylene glycol, was prepared as follows. Ina one-liter Parr reactor equipped with a heated bottom drain valve, highviscosity double turbine agitator, and distillation receiver with a coldwater condenser was charged 388 grams of dimethylterephthalate, 104.6grams of sodium 5-sulfoisophthalic acid, 322.6 grams of 1,2-propanediol(1 mole excess of glycols), 48.98 grams of diethylene glycol, (1 moleexcess of glycols), trimethylolpropane (5 grams) and 0.8 grams ofbutyltin hydroxide oxide as the catalyst. The reactor was heated to 165°C. with stirring for 3 hours and then again heated to 190° C. over a onehour period, after which the pressure was slowly reduced fromatmospheric pressure to about 260 Torr over a one hour period, and thenreduced to 5 Torr over a two hour period. The pressure was then furtherreduced to about 1 Torr over a 30 minute period and the polymer wasdischarged through the bottom drain onto a container cooled with dry iceto yield 460 grams of sulfonated-polyester resin. The branchedsulfonated-polyester resin had a glass transition temperature measuredto be 54.5° C. (onset) and a softening point of 154° C.

Example 2

This Example shows the preparation of a branched sodio sulfonatedamorphous polyesters-silver nanoparticles (BSPE-AgNPs) compositeemploying trisodium citrate as the reducing agent.

The reaction was carried out in a 3 necked, 500 mL round bottom flaskequipped with an overhead stirrer, reflux condenser, thermocouple, hotplate, and nitrogen entrance (the condenser acted as the nitrogen exit).About 320 mL of DIW was charged into the flask at room temperature (22°C.). The heat was turned on set to 90° C. and nitrogen was run throughthe system (RPM=250). Once the temperature had stabilized, 100.0 g ofsolid BSPE was added to the system in a finely ground state (RPM=300).The solution became hazy and had a blue tinge. After 1.5 hours, 1.00 gAgNO₃ dissolved in 6.0 mL DIW was added dropwise to the solution at arate of approx. 1 drop/second (RPM=387). The solution became slightlydarker (brownish). After 10 minutes, 52.5 mL of 1% (w/w %) trisodiumcitrate solution (reducing agent) was added to the system dropwise at arate of 1 drop per second. Upon complete addition, the solution wasstirred at 90° C. for 2 hours (RPM=300). The solution was allowed tocool to room temperature (RPM=386). The final appearance of the emulsionwas a light brown opaque solution. The solids content of the emulsionwas 27.70%, the D50 was 69.6 nm, the pH was 4.77 and the zeta potentialwas −58.6 mV with a zeta deviation of 7.87 mV (breadth of distribution).The percentage of silver in the BSPE-AgNP composite was 0.28% w/w % or0.0235 M. The amount of silver present in the particle was analyzed tobe 2413 ppm by inductively coupled plasma (ICP) or 0.2413%.

Example 3

This Example shows the preparation of a branched sodio sulfonatedamorphous polyesters-silver nanoparticles (BSPE-AgNPs) powder.

Into a 500-liter glass reactor was added 108.30 g of distilled waterwith 108.30 g BSPE-AgNP composite obtained from Example 2 to give atotal solids of 13.85%. The reactor was fitted with a mechanicalagitator and equipped with a single pitched blade impellor. The mixturewas initially agitated at 250 rpm and heated via an electric heatingmantle to 60° C. After 20 minutes, once the temperature of the solutionreached 60° C., the rpm was increased to 400 and the zinc acetatesolution (6 g of zinc acetate dihydrate in 100 g of DI water) additionwas commenced. After 100 minutes all the zinc acetate solution was addedand the temperature was increased by 2 degrees to 62° C. The particlesize as measured by a Beckman Coulter Counter was found to be 15.0microns with a geometric standard deviation (GSD) by volume to be 1.30and GSD by number to be 1.25. The temperature was increased anotherdegree to 63° C. and particle growth was monitored via the CoulterCounter. After 3 hours, the heat was turned off and the reactor contentswere cooled to ambient temperature. The final particle size was 20.0micron with a GSDv of 1.30 and a GSDn or 1.30. The particle wasdischarged from the reactor and the particles were filtered from themother liquor and washed 2 times with distilled water (DIW). The finalparticle was redispersed into 200 mL of deionized water, frozen viashell-freezer and placed on a drier for 3 days to result in dryparticles to be used for SLS additive manufacturing.

Example 4

This Example shows wet deposition of BSPE-AgNPs antibacterial particlesto mimic glass microfiber membrane fusing.

A suspension of the particles prepared in Example 3 was prepared inwater containing a small amount of Triton-X 100 surfactant. An amount ofthis suspension corresponding to 9.62 mg of particles was passed througha glass microfiber membrane through a cup with an exposed surface areaof 9.62 cm². The retained particles and filter paper were dried at roomtemperature, then enveloped in Mylar film and passed through a GBClaminator set to 120° C.

Results after 3 days of incubation at 37° C. confirmed that the fusedBSPE-AgNP particles showed no bacteria growth around the particle swatchor on the swatch itself. This zone of inhibition or “halo-effect” isquite large which means that the silver ions are easily released fromthe particles over a short period of time.

Example 5

This Example shows the fabrication of filaments.

The dried particles obtained from Example 4 were fed into the melt flowindex (MFI) instrument (extrusion plastometer) and equilibrated at 90°C. for 6 minutes. The material was then extruded with a 17 kg weightthrough a 2 mm diameter die to fabricate the FDM filament forantibacterial testing. FIG. 4 is a photo image showing the BSPE-AgNPsantibacterial particles of Example 3 being fused onto a glass microfibermember.

Example 6

This Example shows the antibacterial testing of filaments

A 200 mm Pyrex® glass tube is filled with Bacto™ Tryptic Soy Broth and afilament from Example 4 is placed in the glass tube. The glass tube issealed with a rubber stopper and being incubated at 37° C. and 90%humidity for 14 days. A control sample of BSPE filament (from Example 1)containing no AgNPs is also treated to the same incubation procedure.After the incubation period, the tubes are visually analyzed forturbidity. Prior to any filament incubation, the soy broth or TSB istransparent. Once the TSB is exposed to bacteria or fungi, the organismswill turn the liquid turbid due to reproduction/multiplication ofbacteria. Another indicator of bacterial growth is accumulation ofprecipitation that will settle to the bottom of the test tube. Thefilament made with the BSPE-AgNPs in Example 4 shows no signs ofbacterial contamination while the non-AgNP containing BSPE show bothturbidity and precipitation indicating a lack of antibacterial activity.

What is claimed is:
 1. A composite filament for use in fused depositionmodelling, comprising: a sulfonated polyester matrix; and a plurality ofsilver nanoparticles dispersed within the matrix, wherein the silvernanoparticle is present in the composite filament in a range from about0.5 ppm to about 50,000 ppm; and further wherein the composite filamenthas a diameter of from about 0.5 mm to about 5 mm.
 2. The compositefilament of claim 1, wherein the sulfonated polyester has a glasstransition (Tg) temperature of from about 45° C. to about 95° C.
 3. Thecomposite filament of claim 1, wherein the sulfonated polyester matrixcomprises a branched polymer.
 4. The composite filament of claim 1,wherein the sulfonated polyester matrix comprises a linear polymer. 5.The composite filament of claim 1, wherein the composite filament is inthe form of a cylinder having a diameter of about 0.5 mm to about 5.0mm.
 6. The composite filament of claim 1, wherein the sulfonatedpolyester matrix comprises hydrogen or a salt of a random sulfonatedpolyester, wherein the sulfonated polyester is selected frompoly(1,2-propylene-5-sulfoisophthalate),poly(neopentylene-5-sulfoisophthalate),poly(diethylene-5-sulfoisophthalate),copoly(1,2-propylene-5-sulfoisophthalate)-copoly-(1,2-propylene-terephthalatephthalate),copoly(1,2-propylene-diethylene-5-sulfoisophthalate)-copoly-(1,2-propylene-diethylene-terephthalatephthalate),copoly(ethylene-neopentylene-5-sulfoisophthalate)-copoly-(ethylene-neopentylene-terephthalate-phthalate),copoly(propoxylated bisphenol A)-copoly-(propoxylated bisphenolA-5-sulfoisophthalate),copoly(ethylene-terephthalate)-copoly-(ethylene-5-sulfo-isophthalate),copoly(propylene-terephthalate)-copoly-(propylene-5-sulfo-isophthalate),copoly(diethylene-terephthalate)-copoly-(diethylene-5-sulfo-isophthalate),copoly(propylene-diethylene-terephthalate)-copoly-(propylene-diethylene-5-sulfoisophthalate),copoly(propylene-butylene-terephthalate)-copoly(propylene-butylene-5-sulfo-isophthalate),copoly(propoxylated bisphenol-A-fumarate)-copoly(propoxylated bisphenolA-5-sulfo-isophthalate), copoly(ethoxylatedbisphenol-A-fumarate)-copoly(ethoxylatedbisphenol-A-5-sulfo-isophthalate), copoly(ethoxylatedbisphenol-A-maleate)-copoly(ethoxylatedbisphenol-A-5-sulfo-isophthalate), copoly(propylene-diethyleneterephthalate)-copoly(propylene-5-sulfoisophthalate),copoly(neopentyl-terephthalate)-copoly-(neopentyl-5-sulfoisophthalate),and mixtures thereof.
 7. The composite filament of claim 6, wherein thesalt is selected from the group consisting of sodium, lithium andpotassium.
 8. The composite of claim 1, wherein the sulfonated polyestermatrix comprises a polyol monomer unit selected from the groupconsisting of trimethylolpropane, 1,2-propanediol, diethylene glycol,and combinations thereof.
 9. The composite of claim 1, wherein thesulfonated polyester matrix comprises a diacid monomer unit selectedfrom the group consisting of terephthalic acid, sulfonated isophthalicacid, and combinations thereof.
 10. A method of producing a compositefilament, comprising: heating a sulfonated polyester resin in anorganic-free solvent; adding a solution of silver (I) ion to the heatedresin in the organic-free solvent to form a mixture; adding a solutionof a reducing agent to the mixture, thereby forming an emulsion ofparticles comprising a sulfonated polyester matrix and a plurality ofsilver nanoparticles disposed within the sulfonated polyester matrix;aggregating the emulsion of particles to form aggregated particles;coalescing the aggregated particles to form coalesced particles; washingthe coalesced particles, thereby forming a composite powder; andextruding the composite powder to produce the composite filament. 11.The method of claim 10, wherein the heating of the sulfonated polyesterresin is conducted at a temperature from about 65° C. to about 90° C.12. The method of claim 10, wherein the aggregating is conducted at atemperature of from about 30° C. to about 80° C.
 13. The method of claim10, wherein the coalescing is conducted at a temperature of from about30° C. to about 95° C.
 14. The method of claim 10, wherein a source ofsilver (I) ion is selected from silver nitrate, silver sulfonate, silverfluoride, silver perchlorate, silver lactate, silver tetrafluoroborate,silver oxide and silver acetate.
 15. The method of claim 10, wherein thereducing agent is selected from ascorbic acid, trisodium citrate. 16.The method of claim 10, wherein the sulfonated polyester resin is abranched polymer.
 17. The method of claim 10, wherein the sulfonatedpolyester resin is a linear polymer.
 18. The method of claim 10, whereinthe sulfonated polyester matrix comprises hydrogen or a salt of a randomsulfonated polyester, wherein the sulfonated polyester is selected frompoly(1,2-propylene-5-sulfoisophthalate),poly(neopentylene-5-sulfoisophthalate),poly(diethylene-5-sulfoisophthalate),copoly(1,2-propylene-5-sulfoisophthalate)-copoly-(1,2-propylene-terephthalatephthalate),copoly(1,2-propylene-diethylene-5-sulfoisophthalate)-copoly-(1,2-propylene-diethylene-terephthalatephthalate),copoly(ethylene-neopentylene-5-sulfoisophthalate)-copoly-(ethylene-neopentylene-terephthalate-phthalate),copoly(propoxylated bisphenol A)-copoly-(propoxylated bisphenolA-5-sulfoisophthalate),copoly(ethylene-terephthalate)-copoly-(ethylene-5-sulfo-isophthalate),copoly(propylene-terephthalate)-copoly-(propylene-5-sulfo-isophthalate),copoly(diethylene-terephthalate)-copoly-(diethylene-5-sulfo-isophthalate),copoly(propylene-diethylene-terephthalate)-copoly-(propylene-diethylene-5-sulfoisophthalate),copoly(propylene-butylene-terephthalate)-copoly(propylene-butylene-5-sulfo-isophthalate),copoly(propoxylated bisphenol-A-fumarate)-copoly(propoxylated bisphenolA-5-sulfo-isophthalate), copoly(ethoxylatedbisphenol-A-fumarate)-copoly(ethoxylatedbisphenol-A-5-sulfo-isophthalate), copoly(ethoxylatedbisphenol-A-maleate)-copoly(ethoxylatedbisphenol-A-5-sulfo-isophthalate), copoly(propylene-diethyleneterephthalate)-copoly(propylene-5-sulfoisophthalate),copoly(neopentyl-terephthalate)-copoly-(neopentyl-5-sulfoisophthalate),and mixtures thereof.
 19. An article comprising: a composite filamentcomprising: a sulfonated polyester matrix; and a plurality of silvernanoparticles dispersed within the matrix; wherein the silvernanoparticle is present in the composite filament in a range from about0.5 ppm to about 50,000 ppm; and further wherein the composite filamenthas a diameter of from about 0.5 mm to about 5 mm.
 20. The article ofclaim 19, wherein the article is selected from the group consisting of abiochemical sensor, an optical detector, an antibacterial, a textile, acosmetic, an electronic component, a fiber, and a cryogenicsuperconducting material.